A fundamental problem with membrane electrode assemblies, such as the membrane electrode assemblies of polymer electrolyte membrane fuel cells, is the final inspection, as the membrane can be damaged, and owing to the electrode layers on both sides thereof, this damage is not detectable by visual inspection.
A large number of membrane electrode assemblies, for example, in the order of magnitude of 100, are used in a fuel cell stack. One defective membrane electrode assembly can result in failure of the entire stack.
Therefore, it is important to test a fabricated membrane electrode assembly for its operability. It is known to make spot checks on membrane electrode assemblies after production and to electrochemically characterize these. Afterwards, the tested sample is no longer usable.